IL-20, a member of the IL-10 family, is a proinflammatory cytokine involved in the pathogenesis of various inflammation-associated diseases, e.g., rheumatoid arthritis and osteoporosis.
Rheumatoid arthritis, the most common inflammatory arthritis, is characterized by infiltration of mononuclear phagocytes, lymphocyts, and neutrophils into synovial membranes and resultant intense inflammation in synovial joints. Recent studies show that a number of cytokines and chemokines, e.g., members of the IL-10 family, play important roles in the development and progression of this disease.
Osteoporosis is a disease characterized by low bone mass and loss of bone tissue, resulting in weak and fragile bones. Net bone loss can be induced by various factors, e.g., low levels of estrogen, inadequate up take of calcium and vitamin D, and inflammation.